1. Field of the Invention
The invention relates to a method and apparatus for the separation or enrichment, with the aid of high-intensity light source, such as lasers, especially, of isotopes which are bound to single-isotope substances and which form therewith a mixture of compounds.
2. Description of the Prior Art
The use of such high-intensity light sources for the separation of isotopes has previously been proposed, for example, in German Published Prosecuted Applications DT-OS No. 1,959,767 and DT-OS No. 2,150,232. The proposals for uranium enrichment contained therein start with uranium hexafluoride, which has a particularly high vapor pressure. By selective excitation of the U.sup.235 F.sub.6 compound, for example, by means of laser light of a frequency which corresponds to a known rotation vibration line of this isotope compound, selective excitation is achieved in such a manner that these excited molecules react with a suitable reaction partner to form another compound. The new compound can then be taken from the mixture of the starting materials by chemical or chemical-physical means. Since the frequency shift between the rotation vibration lines of the uranium isotope compounds is relatively small and there are very many rotation vibration lines, it is difficult to find particularly well suited frequencies.
It is also possible to consider uranium compounds for their suitability with respect to isotope separation by laser beams. For example, it has previously been proposed to use UCl.sub.6 or UF.sub.5 Cl for this purpose. These compounds, however, have further inherent problems, as the elements bound to the uranium are in themselves not single-isotope elements, i.e., not anisotopic elements. Since there elements possess several isotopes, there are additional rotation lines, which further add to the above mentioned difficulties.
It has therefore been proposed to overcome these difficulties by another starting compound of uranium, which meets the following requirements:
1. it must be gaseous,
2. in addition to uranium, it must contain only such atoms which do not occur in nature as different isotopes, and therefore are single-isotope elements, i.e. anisotopic elements, and
3. the optical absorption spectrum must be such that at least one wavelength is absorbed by one of the two possible uranium compounds predominantly or exclusively.
One suitable uranium compound has now been found to be uranium pentafluoride UF.sub.5 which, like UF.sub.6, contains only an anisotopic element, besides uranium. However, it has the great disadvantage that it has practically no vapor pressure at room temperature.